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How to Fix External Memory Access Failures on LPC2138FBD64-01EL

How to Fix External### Failures213F6401 access on LPC864EL

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** steps the specific hardware setup for any further the LPC2138 matches the requirements of the external memory. Ensure that the microcontroller's clock source and frequency are properly configured to match the external memory's needs.

Look for any mismatches in the frequency or timing parameters in the PLL (Phase-Locked Loop) configuration.

Solution: Adjust the microcontroller’s clock settings or the external memory’s clock if necessary. Consult the datasheets of both the LPC2138 and the external memory device for the correct clock parameters.

Step 5: Review Timing Parameters

Action: Timing parameters are crucial for memory access. Verify the timing settings, such as the address strobe, data strobe, and read/write latencies, in the configuration registers.

Use an oscilloscope to capture and analyze the signals between the microcontroller and the external memory. This will help you identify any timing violations.

Solution: Adjust the memory timing settings in the EMI configuration register to meet the requirements of the external memory. Fine-tune wait states, address setup, and hold times based on the memory’s datasheet.

Step 6: Test and Debug

Action: After performing the above checks, test the system by accessing the external memory. Use simple read/write operations to verify if the issue has been resolved.

If the failure persists, use a debugger or serial output to track the execution and determine exactly where the failure occurs.

Solution: If the external memory is still inaccessible, recheck each of the above steps, making sure that all configurations and wiring are correct. Try using a different external memory module to rule out the possibility of faulty hardware.

Conclusion

External memory access failures in the LPC2138FBD64/01EL can be caused by incorrect configurations, faulty connections, improper power supply, clock mismatches, or timing issues. By following a systematic troubleshooting approach—verifying configuration settings, inspecting connections, ensuring stable power, and analyzing timing—you can identify and resolve the issue. By carefully applying the above solutions step-by-step, you'll restore proper memory access functionality and ensure your system runs smoothly.